When samples are to be analyzed for organic trace compounds, the samples are typically extracted with an organic solvent. The solvent extracts the compounds from the sample, due to selective chemistry. Before the extract can be analyzed, all residual water should preferably be removed from the extracting solvent. This is due to the adverse effect residual water can have on the analytical instruments that are used to analyze the sample.
U.S. Pat. No. 6,749,755 describes an apparatus and method for separating residual water from a solvent. The device comprises a reservoir containing a solution comprising solvent containing residual water, the reservoir having an opening to allow the solution to drain from the reservoir. A membrane layer is provided comprising a layer of fluoropolymer material, wherein the membrane material has an IPA Bubble Point of greater than or equal to 25 psi. The membrane is positioned in series with the reservoir opening. Vacuum is generated on one side of the membrane layer wherein the solvent containing water passes through the membrane therein removing water from the solvent to provide a solvent with a water level of less than or equal to 1.0 ppm.